The present invention relates to valve actuators, and more particularly, to an auxiliary actuator for operating a valve from a location remote from the valve and wherein the valve is itself of a type which is intended to operate automatically in response to the occurrence of an exigent character, such as fire, the auxiliary valve actuator providing also such actuation upon the same occurrence at the location of the auxiliary actuator as well as permitting manual actuation of the valve.
In Lyons U.S. Pat. No. 4,275,754, there is disclosed an automatic valve actuator of the type for actuating a rotary-actuated valve such as a ball valve, in the event of fire or other exigency. Such valves are used, for example, in the chemical industry for controlling the flow of various sorts of fluids, such as flammable volatiles. The valve actuator which includes a fusible link or other type of releasable link which can release the mechanism in the event of fire or other situation. For example, it may be electrically released. It may be desired, in the event of such an occurrence, that the valve either fail closed, in order to shut off the flow of fluid through the valve, or else to fail in an "as was" position. In any event, the valve is automatically actuated by such mechanism in order to return to a condition in which the valve should be for such an occurrence, whether it be fire, smoke, excessive heat or otherwise.
There are, however, many installations where it is necessary or desirable to provide for actuation of the valve from a remote location. Thus, an auxiliary actuator must be provided which itself is capable of actuating the otherwise automatically-actuated valve in order to close the valve (or return it to an "as was" status) in the event of an exigency such as fire. However, in such installations, the auxiliary actuator must not interfere with the normal actuating movement of the valve, whether such be manually effected or automatically carried out. Accordingly, the valve is to remain actuated either manually, or in response to its own built-in automatic actuator (as in accordance with said Lyons U.S. Pat. No. 4,275,754) or automatically in response to the operation of the auxiliary actuator.
Accordingly, an object of the invention is the provision of an auxiliary remote valve actuator for actuating a rotary valve, and specifically such an auxiliary actuator which may be used for actuating a valve of the type already equipped with an automatic valve actuator, but which also can be utilized with valves which do not have such an automatic valve actuator built in; which will permit auxiliary actuation of the valve from a location remote from the valve, whether separated by a relatively short distance or by a substantial distance; which permits not only auxiliary automatic actuation of the valve in response to an exigency such as fire, or the like, but also permits a remote manual actuation of the valve; which permits auxiliary actuation to be added to a rotary-actuated type of valve in numerous kinds of installations and which accordingly provides extremely facile operation without critical adjustment; which does not interfere with normal actuation, whether manual or automatic, of a valve with which it is interconnected; and which may be used with a variety of different types of valves, such as conventional rotary valves of the quarter-turn ball, butterfly or plug valve type, for automatic actuation thereof; and which permits still other types of actuation to be carried out, such as, for example, the addition of tandem auxiliary actuators along a single cable, or connection of such cable to other structures and devices, such as vehicles, for actuation of the valve.
It is also an object of the invention to provide such an auxiliary remote valve actuator which complies with occupational safety and health requirements, which is inherently safe and reliable in operation; and which, in addition to relative simplicity and economy of construction requiring relatively few parts and simple manufacture, it is entirely durable, long-lasting and reliable in operation.
Other objects will be apparent and in part pointed out hereinbelow.